A plot could revolve around a time - travel scenario. Hyuuga and Kuroko are sent back to the early days of the basketball team. They use their current knowledge and skills to improve the team from the very beginning. Along the way, they rely on each other a great deal, and their relationship evolves from just teammates to really good friends who trust each other completely.
One plot idea could be that Kuroko and Akashi have to team up for an unexpected street basketball tournament against a group of international players. They start off with a lot of friction due to their past rivalry but gradually learn to work together and discover new aspects of each other's playing styles.
One plot idea could be that Kise, in his yandere state, becomes overly possessive of Kuroko. He might try to isolate Kuroko from his other friends, like the Generation of Miracles. For example, he could spread false rumors about them to make Kuroko distance himself. Another idea is that Kise secretly follows Kuroko everywhere, taking pictures of him without his knowledge and creating a sort of 'private collection' which he treasures dearly. It could also be a story where Kise's yandere tendencies are triggered by another character showing too much interest in Kuroko, leading to a conflict between his love and his dark side.
One idea could be that the male OC is a transfer student with a unique basketball skill, like a super - fast dribble. He challenges the Generation of Miracles in a friendly match and through his determination and teamwork, he earns their respect.
Maybe a plot where they time - travel back to their childhoods. They see how they were as kids and how their paths were always meant to cross. This could explore their individual growth and how it led to their partnership in basketball. They could also use their current knowledge to help their younger selves in some way, like giving tips on basketball techniques.
One plot could be that an evil organization creates a clone of Mikan. Natsume has to figure out which is the real Mikan. This leads to a lot of confusion and also some moments where he realizes how much he truly knows and cares about the real Mikan. Another idea is that Natsume and Mikan get trapped in a dream world created by a powerful Alice user. In this world, their deepest desires and fears are manifested. They have to work together to break free from this world, which involves facing their own insecurities. And for a third plot, there could be a story where Mikan discovers she has a rare and powerful secondary Alice that only Natsume can help her control. This creates a new dynamic in their relationship as they train together to master this new power.
One idea could be an OC who is a transfer student with a unique basketball skill, like being able to predict opponents' moves from their body language. This OC could join Seirin and form a special bond with Kuroko and the team, helping them in tough matches against strong opponents.
One idea could be exploring a 'what if' scenario where Kuroko has a new, unexpected special move that changes the whole dynamic of the game. Maybe it's a super - fast pass that can't be intercepted easily.
A crossover with 'Slam Dunk' would also be great. Maybe the teams in Kuroko no Basket meet the Slam Dunk characters in a streetball tournament. There could be intense rivalries and exchanges of basketball techniques. For example, the flashy moves of the Slam Dunk players could inspire the Kuroko no Basket characters to add some new elements to their own game.
One idea could be a crossover with 'Haikyuu!!'. The characters from Kuroko no Basuke could have a friendly match or a training camp together with the Haikyuu!! teams. They could learn different playing styles from each other and develop new strategies.
Another plot could involve the reader being a talented basketball player from another school who transfers. The Kuroko no Basket characters are initially skeptical but as they see the reader's skills on the court, they become intrigued. Along the way, friendships develop and there could be some light - hearted rivalries and team - building moments.